We report a 73-year-old Japanese man with early onset pure red cell aplasia (PRCA) caused by subcutaneous administration of recombinant epoetin-β. Two months after the start of epoetin therapy, he developed PRCA. Anti-erythropoietin (EPO) antibody, detected in the patient's serum by enzyme immunoassay and radioimmunoprecipitation method, inhibited EPO-dependent growth of AS-E2 cells in vitro. Treatment with prednisone (1 mg/kg) significantly reduced antibody levels 3 months later. It is important to have an awareness of antibody-mediated PRCA. Our case shows that subcutaneous epoetin administration produces this complication in the early period of therapy.
